Please explain

"KeithK" wrote in message
...
In article ,
(Kevin Brooks) wrote:



I believe what he was referring to is the fact that red, green, and
blue are *the* primary colors.
Er, isn't that red, green, and yellow?

Actually, red, green blue are "the primary colors of light" but
red, yellow and blue serve the same purpose for pigments.

The red, green blue thing originates in the human eye. In a "normal,
healthy eye" there are four types of receptors: one type is most
sensitive in the red region of the spectrum, one in the green, one
in the blue and one (that provides night vision) is sensitive across
a the great swath of the visible spectrum up into the ultra violet.
None of the types have exactly sharp cut offs in sensitivity and in
fact the color cells have a good deal of over lap in their sensitivities.
It's because of this over lap that mixing the "primary colors" fools
the eye into seeing the infinite colors and shades that lie between.